An engineer deploys a Cisco Expressway edge server for a customer who wants to utilize all feature on the server. Which feature does the engineer configure on the Expressway edge?

A VTC (Video Teleconferencing) bridge is a media resource for multi-point video conferences, typically provided by dedicated hardware or software (e.g., Cisco Meeting Server), not directly a feature of Expressway-E.

While Expressway can facilitate H.323 calls, direct H.323 endpoint registration is primarily handled by gatekeepers or CUCM for internal endpoints, and Expressway's role is more about traversal for various protocols, not direct H.323 endpoint registration on the edge itself.

A SIP gateway for PSTN providers is typically implemented on a Cisco IOS gateway or a dedicated Session Border Controller (SBC) that connects to the PSTN, not a core function of Expressway-E.

Mobile and Remote Access (MRA) is a primary feature enabled by Cisco Expressway-E, allowing endpoints outside the corporate network to register with Cisco Unified Communications Manager and IM&Presence services. This provides secure access to calling, presence, and messaging services for remote and mobile users.